Solar panel

ABSTRACT

A solar panel that utilizes the sun&#39;s rays to heat a liquid to be used for providing heat or hot water includes front and rear parallel clear plastic panels. The front panel is intended to face the sun and is substantially transparent so that the sun&#39;s rays can pass there through The rear panel has a reflective coating thereon wherein rays from the sun are reflected back toward the space between the panels. Located within the space are a plurality of conduits formed by a plurality of internal walls that extend between the panels and the left and right side edges. Within the conduits is a darkened oily liquid that is heated by the incoming rays of the sun and the rays reflected by the rear panel. In a preferred embodiment, the front and rear panels and the internal walls are extruded as a single unit.

TECHNICAL FIELD

The present invention is directed toward a device in the nature of asolar panel of the type that utilizes the sun's rays to heat a liquid tobe used for providing heat or hot water to a home or other building.

BACKGROUND ART

Solar panels, also known as solar heat collectors, of the type statedgenerally above have been known for many years. During the 1970's and1980's a significant number of different solar panels were constructedand used as a result of the intensive energy debate which took placeduring this period with regard to alternative renewable sources ofenergy. Many of the solar panels built during that period weremanufactured in relatively small production series in an oftenunprofessional manner, which in time caused problems with water leakageamongst other things.

The early solar collectors were generally constructed of rigid materialssuch as glass and metal tubing. Consequently, they were heavy andcumbersome to handle and install, and were also undesirably expensive toconstruct and to use. Non-rigid solar collectors constructed of plasticmaterials have also been proposed but none has proven successful.

In one previously known system, a panel is extruded from a thermoplasticmaterial with a plurality of transparent or translucent channels formedtherein. The back surface of the panel is darkened so as to absorb lightenergy. A liquid flowing through the channels is heated by the sun andby the darkened back panel. While this may be an improvement on otherprior art systems, it is still inefficient as much of the energy fromthe sun's rays is used merely to heat the darkened back panel and is nottransferred to the liquid.

With renewed interest in solar energy because of increasing energy costsand the desire to not to rely on foreign oil, a need exists for animproved light weight and inexpensive solar panel that efficientlytransfers energy from the sun's rays to the liquid to be heated.

DISCLOSURE OF THE INVENTION

The present invention is intended to overcome the deficiencies of theprior art discussed above. It is an object of the present invention toprovide a solar panel that utilizes the sun's rays to heat a liquid tobe used for providing heat or hot water.

It is another object of the present invention to provide a solar panelthat utilizes the sun's rays to heat a liquid to be used for providingheat or hot water and that is efficient and inexpensive to produce.

It is a still further object of the present invention to provide a solarpanel that utilizes the sun's rays to heat a liquid to be used forproviding heat or hot water, that can be easily mass produced and whichrequires little or no maintenance.

In accordance with the illustrative embodiments demonstrating featuresand advantages of the present invention, there is provided a solar panelthat utilizes the sun's rays to heat a liquid to be used for providingheat or hot water. The solar panel includes front and rear parallel butspaced apart clear plastic panels. Each panel has a front surface, aback surface and left and right side edges. The front panel is intendedto face the sun and is substantially transparent so that the sun's rayscan pass therethrough. The rear panel has a reflective coating thereonwherein rays from the sun that pass through the front panel and throughthe space between the panels is reflected back toward the space. Locatedwithin the space between the panels are a plurality of conduits formedby a plurality of internal walls that extend between the front and rearpanels and between the left and right side edges. Within the conduits isa darkened oily liquid that is heated by the incoming rays of the sunand by the rays reflected by the rear panel. In a preferred embodiment,the front and rear panels and the internal walls are extruded as asingle unit. The goal of the solar panel of the invention is to absorbbetween approximately 60 percent to approximately 98 percent of thesun's energy on the first pass and the rest as it is reflected back.

Other objects, features, and advantages of the invention will be readilyapparent from the following detailed description of preferredembodiments thereof taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustration the invention, there are shown in theaccompanying drawings one forms which is presently preferred; it beingunderstood that the invention is not intended to be limited to theprecise arrangements and instrumentalities shown.

FIG. 1 is a front perspective view shown somewhat schematically of asolar panel showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a cross-sectional view taken through the lines 3-3 of FIG. 1,and

FIG. 4 is a cross-sectional view taken through the lines 4-4 of FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to the several drawings in detail wherein like referencenumerals have been used throughout the various figures to designate likeelements, there is shown in FIGS. 1 and 2 a solar panel of the type thatutilizes the sun's rays to heat a liquid to be used for providing heator hot water to a home or other building constructed in accordance withthe principles of the present invention and designated generally as 10.The solar panel 10 is comprised essentially of a front panel 12 and arear panel 14. As shown most clearly in FIGS. 3 and 4, the front panel12 has a front surface 16 and a back surface 18. It also has a left sideedge 20 and a right side edge 22 as shown in FIG. 1. The front panel 12is substantially transparent and is intended to face the sun so thatthey sun's rays 24 can pass therethrough substantially uninterrupted.

Similarly, the rear panel 14 includes a front surface 26, a back surface28 and left and right side edges 30 and 32, respectively. The rear panel14 is arranged parallel to but spaced apart from the front panel 12 soas to leave a space 34 in between the two panels. As shown most clearlyin FIGS. 3 and 4, the back surface 28 of the rear panel 14 has areflective coating 36 thereon. It is possible, however, to have thereflective surface 36 be spaced slightly from the back surface 28 of therear panel with an air or vacuum in the space in between them. In anycase, rays 24 from the sun that pass through the front panel 12 andthrough the space 34 strike the reflective coating 36 and are reflectedback toward the space 34. The reflective coating 36 can be comprised ofa coating known in the art such as a bright white paint or the like, asilver-mirrored finish or any other material that will reflect impinginglight effectively.

Located within the space 34 between the front and back panels 12 and 14are a plurality of conduits such as shown at 38, 40 and 42 (for example)in FIGS. 1 and 4. The conduits are formed by a plurality of internalwalls such as shown at 44 and 46 that extend between the front and rearpanels 12 and 14. These internal walls 44 and 46 also extend to the leftand right side edges of the front and right panels.

As shown in FIGS. 1 and 2, the side edges of the solar panel are fittedinto elongated openings in tubular pipe members 48 and 50. The side endsof the conduits 38, 40 and 42, for example, are open and communicatewith the interior of the pipe members 48 and 50. As a result, and asshown diagrammatically in FIG. 1, a liquid 52 passing into the interiorof the pipe member 50 passes through each of the conduits and out theother end into the interior of the pipe member 48.

It should be noted that while the liquid 52 is shown passing throughonly some of the channels in the solar panel, this is for illustrationand clarification only. The liquid 52 will, of course, pass through allof the channels. Furthermore, while the arrangement shown in FIG. 1 hasthe various channels arranged in parallel so that liquid 52 passes inthe same direction through each of them, it is also within the scope ofthe present invention to arrange the numerous channels in series byconnecting alternate ends of the channels together. In this way, theliquid will pass through the first channel in one direction, through thesecond channel in the other direction and back and forth until it exits.

The liquid 52 is preferably oil-based liquid which can be, for example,corn oil, soy oil or sunflower seed oil. It has been found that mineraloil is most suitable. Other liquids can, however, be substituted. Insome climates, for example, it may be preferable to use water alone orin combination with an anti-freeze such as ethylene or propylene glycol.

In order to absorb as much of the sun's energy as possible, the liquid52 is darkened. This can be done utilizing activated carbon, carbonblack or an FDA approved food coloring or dye such as those availablefrom Sensient Technologies Corporation. The most suitable dyes, however,appear to be Sudan Black A soluble dye form BASF or Calcon soluble blackdye from Benckiser of Germany.

The amount of dye and the oil are chosen so that between approximately60 percent to approximately 98 percent of the sun's energy is absorbedon the first pass and the rest is absorbed as the sun's rays or energyis reflected back. In addition, the oil and dye allow for the absorptionof infrared energy from the sun's rays in addition to light in thevisible spectrum

The front panel 12, rear panel 14 and the internal walls 44 and 46 etc.,preferably formed as one piece by an extrusion process well known in theart. Preferably, all of the components are made from a clearthermoplastic material such as a polycarbonate or polymethylmethacrylate (acrylic) material.

As should be readily apparent to those skilled in the art, Applicant hasschematically shown only the essential features of the solar panelitself. Obviously, seals, mounting hardware, an insulated box and thelike will be used as needed. Furthermore, while not specifically shown,the solar panel 10 is intended to be used as part of a closed liquidheating system wherein the darkened liquid 52 heated by the solar panelstructure will transfer heat through a heat exchanger in order toprovide heat or hot water to a dwelling or other building. In addition,the solar panel 10 can be used alone or in combination with a number ofadditional similarly constructed panels and can also be part of abuilding element that forms part of the roof of a building.

The present invention may be embodied on other specific forms withoutdeparting from the spirit or essential attributes thereof andaccordingly, reference should be made to the appended claims rather thanto the foregoing specification as indicating the scope of the invention.

1. A device through which a liquid can be transported and which isintended to face the sun so that the sun's rays can heat the liquid,said device comprising: a substantially transparent container having aspace therein for containing the liquid as it is transported throughsaid device , said container having an inlet and an outlet; a reflectivesurface wherein rays from the sun that pass through said transparentcontainer can be reflected back into said liquid; said liquid beingdarkened to absorb a substantial portion of the sun's rays impingingthereon while allowing some of said rays to pass therethrough to bereflected back into said liquid where it is substantially completelyabsorbed; said container and said liquid being so arranged and designedsuch that between approximately 2% and 40% of the sun's rays passthrough said liquid to said reflective surface to be reflected back tosaid liquid for substantially complete absorption, and means for movingsaid liquid into and out of said space.
 2. The device as claimed inclaim 1 wherein said container has a front panel having a front surface,a back surface, a left side edge and a right side edge, said front panelbeing substantially transparent and being intended to face the sun sothat the sun's rays can pass therethrough.
 3. The device as claimed inclaim 2 wherein said container has a rear panel spaced from said frontpanel to create said space therebetween.
 4. The device as claimed inclaim 2 wherein said front and rear panels are arranged parallel to eachother.
 5. The device as claimed in claim 1 further including a pluralityof conduits within said space, said darkened liquid being containedwithin said conduits.
 6. The device as claimed in claim 5 wherein saidconduits are formed by a plurality of internal walls extending betweensaid front and rear panels.
 7. The device as claimed in claim 6 whereinsaid plurality of internal walls also extend between said left and rightside edges of said front and rear panels.
 8. The device as claimed inclaim 1 wherein said liquid is comprised of oil.
 9. The device asclaimed in claim 8 wherein said oil is mineral oil.
 10. The device asclaimed in claim 1 wherein said liquid is comprised of water.
 11. Thedevice as claimed in claim 10 wherein said liquid further includes ananti-freeze.
 12. The device as claimed in claim 1 wherein said liquidcontains a soluble black dye.
 13. The device as claimed in claim 3wherein said front and rear panels are formed from a clear plastic. 14.The device as claimed in claim 13 wherein said plastic is apolycarbonate.
 15. The device as claimed in claim 6 wherein saidinternal walls are formed of plastic.
 16. The device as claimed in claim15 wherein said front and rear panels and said internal walls areextruded as a single unit.
 17. The device as claimed in claim 3 whereinsaid reflective surface is secured to said rear panel.
 18. The device asclaimed in claim 3 wherein said reflective surface spaced from said rearpanel.
 19. The device as claimed in claim 1 wherein said liquid absorbsenergy outside of the visible spectrum.
 20. The device as claimed inclaim 19 wherein said liquid absorbs energy in the infrared spectrum.